1. Field of the Invention
The present invention relates to curable polytitanosiloxane compositions. More particularly, this invention relates to these curable compositions and a method for curing the compositions to yield materials useful as anti-reflective films and optical coupling devices.
2. Background Information
One type of curable polyorganosiloxane contains repeating units containing three organic groups bonded to the silicon atom, called M units (R.sub.3 SiO.sub.1/2 units), and units of the formula SiO.sub.4/2, referred to as Q units.
Polyorganosiloxanes of this type that are soluble in organic solvents are called MQ resins. For example, in the Silicone Handbook (Nikkan Kogyo Newspaper Co., Ltd.), edited by Kunio Ito, it is noted that this type of MQ resin is used as a hard coating material and as an ingredient of pressure-sensitive adhesive.
In the field of inorganic materials, a material called silica titania, which is made up of Q units and TiO.sub.4/2 units, is known as a heat-resistant glass. With regard to this silica titania, almost nothing has been reported regarding materials in which organic groups are attached to the silicon moiety.
The present inventors have previously succeeded in manufacturing a polytitanosiloxane comprised primarily of M units, Q units and TiO.sub.4/2 units, and have filed a patent application (Japanese Patent Application No. Hei 6[1994]-28346) based on a method for manufacturing these materials. A disadvantage of this polytitanosiloxane is that when it is left uncured following application or molding, it exhibits low strength and poor resistance to solvents and heat-induced degradation.
One objective of the present invention, in view of the aforementioned disadvantages of uncured polytitanosiloxanes, is to provide curable polytitanosiloxane compositions and a method for curing these compositions following application or molding.